From: Paolo Abeni Date: Fri, 21 Oct 2022 22:58:55 +0000 (-0700) Subject: mptcp: factor out mptcp_connect() X-Git-Tag: v6.1-rc5~96^2~41^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=54f1944ed6d2554475f39a4921dc5422fa692c4f;p=platform%2Fkernel%2Flinux-starfive.git mptcp: factor out mptcp_connect() The current MPTCP connect implementation duplicates a bit of inet code and does not use nor provide a struct proto->connect callback, which in turn will not fit the upcoming fastopen implementation. Refactor such implementation to use the common helper, moving the MPTCP-specific bits into mptcp_connect(). Additionally, avoid an indirect call to the subflow connect callback. Note that the fastopen call-path invokes mptcp_connect() while already holding the subflow socket lock. Explicitly keep track of such path via a new MPTCP-level flag and handle the locking accordingly. Additionally, track the connect flags in a new msk field to allow propagating them to the subflow inet_stream_connect call. Fixes: d98a82a6afc7 ("mptcp: handle defer connect in mptcp_sendmsg") Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e33f9ca..f293069 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1698,7 +1698,10 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) lock_sock(ssk); + msk->connect_flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; + msk->is_sendmsg = 1; ret = tcp_sendmsg_fastopen(ssk, msg, &copied_syn, len, NULL); + msk->is_sendmsg = 0; copied += copied_syn; if (ret == -EINPROGRESS && copied_syn > 0) { /* reflect the new state on the MPTCP socket */ @@ -3507,10 +3510,73 @@ static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg) return put_user(answ, (int __user *)arg); } +static void mptcp_subflow_early_fallback(struct mptcp_sock *msk, + struct mptcp_subflow_context *subflow) +{ + subflow->request_mptcp = 0; + __mptcp_do_fallback(msk); +} + +static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + struct socket *ssock; + int err = -EINVAL; + + ssock = __mptcp_nmpc_socket(msk); + if (!ssock) + return -EINVAL; + + mptcp_token_destroy(msk); + inet_sk_state_store(sk, TCP_SYN_SENT); + subflow = mptcp_subflow_ctx(ssock->sk); +#ifdef CONFIG_TCP_MD5SIG + /* no MPTCP if MD5SIG is enabled on this socket or we may run out of + * TCP option space. + */ + if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) + mptcp_subflow_early_fallback(msk, subflow); +#endif + if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) { + MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT); + mptcp_subflow_early_fallback(msk, subflow); + } + if (likely(!__mptcp_check_fallback(msk))) + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE); + + /* if reaching here via the fastopen/sendmsg path, the caller already + * acquired the subflow socket lock, too. + */ + if (msk->is_sendmsg) + err = __inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags, 1); + else + err = inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags); + inet_sk(sk)->defer_connect = inet_sk(ssock->sk)->defer_connect; + + /* on successful connect, the msk state will be moved to established by + * subflow_finish_connect() + */ + if (unlikely(err && err != -EINPROGRESS)) { + inet_sk_state_store(sk, inet_sk_state_load(ssock->sk)); + return err; + } + + mptcp_copy_inaddrs(sk, ssock->sk); + + /* unblocking connect, mptcp-level inet_stream_connect will error out + * without changing the socket state, update it here. + */ + if (err == -EINPROGRESS) + sk->sk_socket->state = ssock->state; + return err; +} + static struct proto mptcp_prot = { .name = "MPTCP", .owner = THIS_MODULE, .init = mptcp_init_sock, + .connect = mptcp_connect, .disconnect = mptcp_disconnect, .close = mptcp_close, .accept = mptcp_accept, @@ -3562,78 +3628,16 @@ unlock: return err; } -static void mptcp_subflow_early_fallback(struct mptcp_sock *msk, - struct mptcp_subflow_context *subflow) -{ - subflow->request_mptcp = 0; - __mptcp_do_fallback(msk); -} - static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) { - struct mptcp_sock *msk = mptcp_sk(sock->sk); - struct mptcp_subflow_context *subflow; - struct socket *ssock; - int err = -EINVAL; + int ret; lock_sock(sock->sk); - if (uaddr) { - if (addr_len < sizeof(uaddr->sa_family)) - goto unlock; - - if (uaddr->sa_family == AF_UNSPEC) { - err = mptcp_disconnect(sock->sk, flags); - sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; - goto unlock; - } - } - - if (sock->state != SS_UNCONNECTED && msk->subflow) { - /* pending connection or invalid state, let existing subflow - * cope with that - */ - ssock = msk->subflow; - goto do_connect; - } - - ssock = __mptcp_nmpc_socket(msk); - if (!ssock) - goto unlock; - - mptcp_token_destroy(msk); - inet_sk_state_store(sock->sk, TCP_SYN_SENT); - subflow = mptcp_subflow_ctx(ssock->sk); -#ifdef CONFIG_TCP_MD5SIG - /* no MPTCP if MD5SIG is enabled on this socket or we may run out of - * TCP option space. - */ - if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) - mptcp_subflow_early_fallback(msk, subflow); -#endif - if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) { - MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT); - mptcp_subflow_early_fallback(msk, subflow); - } - if (likely(!__mptcp_check_fallback(msk))) - MPTCP_INC_STATS(sock_net(sock->sk), MPTCP_MIB_MPCAPABLEACTIVE); - -do_connect: - err = ssock->ops->connect(ssock, uaddr, addr_len, flags); - inet_sk(sock->sk)->defer_connect = inet_sk(ssock->sk)->defer_connect; - sock->state = ssock->state; - - /* on successful connect, the msk state will be moved to established by - * subflow_finish_connect() - */ - if (!err || err == -EINPROGRESS) - mptcp_copy_inaddrs(sock->sk, ssock->sk); - else - inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); - -unlock: + mptcp_sk(sock->sk)->connect_flags = flags; + ret = __inet_stream_connect(sock, uaddr, addr_len, flags, 0); release_sock(sock->sk); - return err; + return ret; } static int mptcp_listen(struct socket *sock, int backlog) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index be19592..6a09ab9 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -285,7 +285,9 @@ struct mptcp_sock { u8 mpc_endpoint_id; u8 recvmsg_inq:1, cork:1, - nodelay:1; + nodelay:1, + is_sendmsg:1; + int connect_flags; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue;